Migratory and lymphoid-resident dendritic cells cooperate to efficiently prime naive CD4 T cells.
To initiate an adaptive immune response, rare antigen-specific naive CD4(+) T cells must interact with equally rare dendritic cells (DCs) bearing cognate peptide-major histocompatibility complex (MHC) complexes. Lymph nodes (LNs) draining the site of antigen entry are populated by lymphoid-resident DCs as well as DCs that have immigrated from tissues, although the requirement for each population in initiating the T cell response remains unclear. Here, we show that antigen processing and presentation by both lymphoid-resident and migratory DCs was required for clonal selection and expansion of CD4(+) T cells after subcutaneous immunization. Early antigen presentation by lymphoid-resident DCs initiated activation and trapping of antigen-specific T cells in the draining LN, without sufficing for clonal expansion. Migratory DCs, however, interacted with the CD4(+) T cells retained in the LN to induce proliferation. Therefore, distinct DC subsets cooperate to alert and trap the appropriate cell and then license its expansion and differentiation.
Allenspach
Eric J
EJ
Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.
Lemos
Maria P
MP
Porrett
Paige M
PM
Turka
Laurence A
LA
Laufer
Terri M
TM
D000818:Animals; D017951:Antigen Presentation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002450:Cell Communication; D002465:Cell Movement; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D055785:Gene Knockdown Techniques; D008198:Lymph Nodes / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology
D010047:Ovalbumin